Racor filters are used to filter fuel, especially diesel fuel, prior to combustion of the fuel, and remove water as well as particulates from the fuel. With Racor filters, a bowl is placed beneath the filter element to collect water which has been separated from the fuel by the filtering process. Periodically, the water is removed from the bowl by opening a normally closed valve in the bottom of the bowl and bleeding water off. The bowl is preferably made of transparent plastic so that water collected therein is visible.
The current practice is to utilize a threaded bowl retainer which has a radially projecting annular shoulder that extends outwardly from the axis of the annular retainer and an axially extending rim which is externally threaded. The shoulder of the adaptor engages an inwardly projecting annular land on the can, which annular land defines a circular opening through which the externally threaded, axially projecting rim extends. In order to keep the rim from rotating with respect to the can, a layer of adhesive is disposed between the annular shoulder of the adaptor and the annular land of the can to lock the adaptor to the can so that when the bowl is screwed onto the externally threaded rim, the adaptor does not rotate.
Utilizing adhesive is a relatively expensive undertaking which can be troublesome and unreliable because of material problems with the epoxy used for the adhesive. Such problems include mixture ratio concerns, problems in dispensing the epoxy, mechanical problems with the dispensing machine and difficulties in curing the epoxy after assembly. Since the only purpose of epoxy is to prevent rotation of the adaptor with respect to the can, it is unnecessary to bond the adaptor to the can for any other purpose. Generally, the elimination of one component, i.e. epoxy improves reliability because it reduces the potential for failure of that component, and thus reduces the chance of failure of the entire assembly. Moreover, there is an advantage in the elimination of both a troublesome process and an expensive sub assembly operation. An additional economic advantage to eliminating epoxy adhesive is the reduction of inventory. Inventory is reduced because the sub assemblies of adaptors and cans no longer must be stored since the components can be delivered directly to the assembly line for final filter assembly.